title: Potential effects of environmental conditions on the efficiency of the antifungal tebuconazole controlling Fusarium verticillioides and Fusarium proliferatum growth rate and fumonisin biosynthesis.
abstract: Fusarium verticillioides and Fusarium proliferatum are important phytopathogens which contaminate cereals in the Mediterranean climatic region with fumonisins. In this study we examined the interaction between the fungicide efficacy of tebuconazole and water potential (Ψw) (-0.7-7.0MPa)×temperature (20-35°C) on growth and FUM1 gene expression by real time RT-PCR (an indicator of fumonisin biosynthesis) in strains of both Fusarium species. Concentrations of tebuconazole required to reduce growth by 50 and 90% (ED50 and ED90 values) were determined. Growth of strains of both species was largely reduced by tebuconazole, with similar efficacy profiles in the interacting water potential×temperature conditions. In contrast, FUM1 expression was not generally reduced by tebuconazole. Moreover, sub-lethal doses in combination with mild water stress and temperatures less than 35°C significantly induced FUM1 expression with slight differences in both species. These results suggest that the efficacy of antifungal compounds to reduce mycotoxin risk would be more effective if consideration is given to both growth rate and toxin biosynthesis in relation to interacting environmental conditions. This is the first study linking fungicide efficacy of tebuconazole with environmental factor effects on control of growth and FUM1 gene expression of F. verticillioides and F. proliferatum.
authors.affiliation: Department of Genetics, Faculty of Biology, Complutense University of Madrid (UCM), José Antonio Novais 12, 28040 Madrid, Spain. patmarin8149@bio.ucm.es
authors.forename: Patricia
authors.initials: P
authors.lastname: Marín
authors.forename: Ana
authors.initials: A
authors.lastname: de Ory
authors.forename: Alejandra
authors.initials: A
authors.lastname: Cruz
authors.forename: Naresh
authors.initials: N
authors.lastname: Magan
authors.forename: M Teresa
authors.initials: MT
authors.lastname: González-Jaén
mesh_terms: D000704:Analysis of Variance; D000935:Antifungal Agents / Q000494:pharmacology*; D004777:Environment; D037341:Fumonisins / Q000378:metabolism*; D005659:Fungicides, Industrial / Q000494:pharmacology; D005670:Fusarium / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D020128:Inhibitory Concentration 50; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature; D014230:Triazoles / Q000494:pharmacology*; D014867:Water / Q000494:pharmacology
chemical_list: D000935:Antifungal Agents; D037341:Fumonisins; D005659:Fungicides, Industrial; D014230:Triazoles; D014867:Water; C087114:tebuconazole
keywords: Environmental conditions; FUM1 expression; Fusarium proliferatum; Fusarium verticillioides; Growth rate; Tebuconazole